The Meaning of the “Marketplace of Ideas” in First Amendment Law

The 1919 First Amendment opinions of Oliver Wendell Holmes and Louis Brandeis comprise the seminal texts in the cannon that now includes hundreds of decisions by the Supreme Court of the United States interpreting the core of the American free speech tradition. The marketplace of ideas metaphor they developed has been invoked constantly by Supreme Court justices in First Amendment cases. It has achieved genuine load-bearing legal significance, particularly in certain arenas of free speech law, and over-arching significance in rendering the entire architecture of modern free speech law reasonably coherent and stable. This essay explores the importance of the marketplace metaphor in three discrete areas of modern free speech law: commercial speech, political campaign finance, and tort liability. While by no means the only arenas in which the marketplace metaphor has exerted important influence, these three exemplars are especially illuminating, exposing at once the strengths and weaknesses of the marketplace metaphor as a persuasive tool for ordering free speech doctrines. The essay then examines the marketplace metaphor from a wide-angle lens, making the argument that it operates to define two of the central continental divides of modern free speech law. The essay goes a long way toward providing a descriptively clear and normatively convincing account of free speech law as it currently stands.